To a first approximation, if the fan is going (and using energy) because the CPU is running hot under load (using energy), doesn’t that give you a hint about battery efficiency?
Two laptop model with the same CPU can have big differences in thermal design, which impacts a lot the fan noise but battery efficiency only in a marginal way.
Effectively the parent is saying 'fan noise is up there with performance as my most important metric in a laptop'.
This may be true for the OP, but it's by no means a universal consideration. Personally, battery life comes before fan noise for me as a metric. YMMV.